System of articulate sound reproduction



Sept. 15, 1931. w sMlTH 1,823,705

SYSTEM OF ARTICULATE SOUND REPRODUCTION Filed Feb. 1, 1930 2Sheets-Sheet 1 INVENTOR Winmu J1 5mm B Sept. 15, 1931. w. 0. SMITH1,823,705

SYSTEM OF ARTICULATE SOUND REPRODUCTION Filed Feb. 1, 1930 2Sheets-Sheet 2 a AA R awoentoz Wi'n/zk/d 17. 51mm, Q sa w Patented Sept.15, 1931 UNITED STATES PATENT OFFICE W'INI'IELD 1). SMITH, OF PEEKSKILL,NEW YORK, ASSIGNOB TO EUGENE A. WIDMANN,

OF NEW YORK, N. Y.

SYSTEM OF ARTIC'U LATE SOUND REPRODUCTION Application filed February 1,1930. Serial No. 425,222.

In the art of sound reproduction as practiced with the instrumentalitiesat present in use, articulation that is created at the source of sound,whether produced by the hu- 5 man voice, or musical instrument, or othermeans, is either imperfectly rendered, or wholly lost. This is due tothe fact that no single reproducin device known to me is of such naturethat it can faithfully repeat all of the great variety of articulations,with or without resonance, found in vocal utterances and in the playingof musical instruments, without obstruction.

The tonal qualities of sound, between high and low pitches, its timbreor tone color, its intensity in varying volume, etc., are quiteincapable of true reproduction through the medium of a single devicewith its obstructing influences.

Therefore, my investigations have led me to devise a system of multiplereproducing devices wherein each device differs from the others in somerespect, and each device is characterized as being capable of faithfully25 reproducing a particular sound quality with maximum eflioiency andintensity.

Since with my invention any desirable number of reproducing devices maybe provided in a group, each one being adapted for 30 the eflicientrepetition of a particular sound quality, it will be apparent that thesystem enables the different qualities of articulated sound to beselectively delivered by their respective most highly efiicientreproducing media.

In carrying out my invention I provide a series of reproducing devices,all differing from one another in some respect. These de-' vices arealike in being tubular, with a larger end to carry the palpitatingmember and a smaller end for sound emission.

As stated these devices all differ from one another. The difference maybe in size alone or in the interior contour of the walls.

The tubular contour interiorly should best be truly concentricthroughout and have a cubical capacity that encompasses an air col umnbest suited to emit at the exit orifice a particular articulated sound,with its pitch 50 sympathies, while presenting no obstruction to freeflow of the sound wave created through the transmitting diaphragm.

As an example of different interior con-- tours which may be employedsome of the reproducing devices may be longitudinally convex to aid inthe true repetition of the softer articulations, such for example as thevocal articulation of the letter W and words beginning therewith likeWho, etc. When the -interior contour of the device is longitudinallyconcave, it is better suited for the emission of harder articualtions,like the letter P and words beginning therewith, such as Pouf, etc. Alsofor true articulated renditions of sounds including both soft and hardarticulations the interior of the device may be a longitudinal compoundof both convex and concave contours.

For instance, a device of compound contours, with a terminal concaveportion, preceded by a convex portion, lends itself to true repetitionof the articulated word Whoopee, while a device of compound contours,with a terminal convex portion, lends itself to true repetition of thearticulated word sound Prewar.

Also, as stated, the qualities of intensity, pitch, timbre, etc., arerendered sensitive to faithful reproduction by providing units in thesystem of varying sizes, and in contracting or expanding the area of theexit orifices.

Furtherin the interest of facsimile articulation the diaphragm orpalpitating member may be of suitable size and form and composed of suchmaterial as will bring it into the closest afiinity with either thevocal cords or reed impulses. Thus, for sharper articulations a stiffermaterial'is more appropriate than for the majority of human voicecharacterizations, either in speech alone or speech Written to a musicalscore.

Another feature of my invention consists in the provision of means forreinforcing the sound production by the diaphragm for delivery throughthe air column in advance thereof. 1 This reinforcing effect is achievedwith the aid of a resilient covering for the opposite side of thediaphragm, to yieldingly confine the air space thereat. For example, aflexible rubber apron stretched across the devices such as may beemployed in my imshown as supported by a casing B, which conprovedsystem, the members of the group represented each having a palpitatingelement or diaphragm, indicated at A, here tains the usualelectro-magnetic actuatin means-all lncluded 1n the same circuit Fig. 2is a diagrammatic view showing sets of articulators having diiferentcontours, each set comprising devices of different sizes.

It will be noted, however, that each member of the group is providedwith a forwardly directed sound delivery device, they being identifiedrespectively by the reference characters D, E and F, and each formedwith different interior contours, which contours all present arelatively constricted emission orifice, indicated respectively at d, e,f and whereby articulated sounds are more efliciently-produced. Asalready set forth the interior wall-surfaces of devices D, E, F allpresent concentric, tubular contours, but longitudinally their contoursdifier, for the pur-- pose of enabling them to reproduce respectivelydifl'erent articulations. Thus, the device D is longitudinally convexedand contracted in its cross-sectional area toward its orifice d; thedevice E is longitudinally con-' caved and contracted in itscross-sectional area toward its orlfice e; and the dev: "e F 1slongitudinally both concaved and convexed and contracted toward itsorifice f, all for the purpose already set forth.

Obviously I am not limited to the particular contours represented forthe interiors of my reproducin devices, since my improved system compreends the use of a group of any desirable number of devices, whereof somemay have the contours illustrated and others variants of said contours,it being necessary that all shall be contracted toward their emissionorifices. While the devices D, E, F are all shown in Fig. 1 as of onesize, it is necessary in articulate sound reproduction that the systemshould comprise a group whose members are of different sizes, some ofsaid members being relatively very small, and

others elatively very large, whereby a pluthe device F, all of difierentsizes. In Fig.

2 I have shown such a group wherein the thirteen devices D, areindicated by the character D with accompanying numerals from 1 to 13 toindicate their respective successive cubical capacities, although forconvenience in illustration not all of the thirteen devices appear inthe drawings.

The thirteen devices E indicated in Fig. 2.

Thus each set of articulators D, E and F comprises devices of variablesize, so that an octave in concert pitch is capable of reproducand F aresimilarly tion with each set.

It will be seen that variable formations should best be matched to'afixed chromatic note in concert pitch so that the cubical air spacewithin each articulator should be as accurate as if it were to be a bellin such musical scale.

This chromatic scale should best be in a very high octave so that thecommon articulation of speech in its highest frequency may be had, andso that if variable pitch is desired, air columns of a shape, form andmaterial may be continued from each periphery of suflicient cubic inchdisplacement to reach the depth of the musical pitch desired in itsfundamental and timbre.

Whereas each articulator has its main fundamental note, as in theconstruction of bells, yet there exist in-each the same characteristicsas in all inclosed pipes, to wit :The natural inherent tendency to emita fundamental and sensation of a lower tone first harmonic, a

perfect upper first harmonic and very positive splits above the secondregister, so that and when used in connection with air columns ofcorrect chromatic compressions a positive fundamental in pitch isachieved and as wide in octave pitch as may be desired, which shouldgive an oscillation test of absolute even peak compression in concertpitch throughout the entire sound range, either in complete range ofmusical chromatics or speech characteristics.

For the purpose of stabilizing the vibratory affect of the diaphragm, aspremised, I have shown at G a membrane of flexible rubber, stretchedover the casing B, at the back of diaphragm A, and secured to saidcasing, said membrane enclosing the area behind the diaphragm andserving to compensate for the resistance presented to the diaphragm bythe air column at the forward side thereof.

Variations within the spirit and scope of my invention are equallycomprehended by. the foregoing disclosure.

I claim:

1. A sound reproducing system comprising a plurality of hollow devices,commonly actuable, Whose emission orifices are smaller than theirreception orifices, and which respectively possesses difierentarticulating characteristics.

2. Articulated sound reproducing means comprising a plurality of hollowdevices, commonly actuable, whose emission orifices are smaller thantheir reception orifices, and which respectively have different interiorsurface contours.

3. Articulated sound reproducing means comprising a pluralit of hollowdevices, commonly actuable, whose emission orifices are smaller thantheir reception orifices, and which are respectively of different sizes.

4. Sound reproducing means comprising a group of articulating devices,commonly actuable, including members varying in their interior surfacecontours, members varying in size, and members varying both, in theirinterior surface contours and in size.

5, The combination with a sound reproducing device including adiaphragm, of articulating means at one side thereof, and pressureequalizing means at the other side.

6. The combination with a sound re roducing device, including a diaphra,o articulating means at one side thereo and a resilient, airtightcovering at the other side.

New York, N. Y., January 30th, 1930.

WINFIELD D. SMITH.

